Finland is the first country in the world to license a spent nuclear fuel encapsulation plant and disposal facility. Posiva Ltd. (Posiva) submitted the construction license application (CLA) in the end of 2012 and Radiation and Nuclear Safety Authority of Finland (STUK) made its’ review of the CLA within next two year and gave the statement and safety evaluation report to Ministry of Economic Affairs and Employment (MEAE) in February 2015. The construction license for Posiva was granted by the Government in November 2015.

STUK started planning the regulatory oversight of construction activities after finishing the CLA review. Regulatory oversight of encapsulation plant construction will follow mainly standard principles for nuclear facilities taking into account the graded approach. Oversight of construction of the underground disposal facility will require novel approach since excavating safety classified rooms in bedrock keeping in mind the long term safety aspects differs from traditional nuclear facility construction.

Posiva has constructed underground rock characterization facility, Onkalo, at the facility site during 2004-2016. STUK has regulated the construction of Onkalo as it would have been a nuclear facility because it was planned from the very beginning to expand the Onkalo in the future for the disposal facility. The gained experience will be used for the future regulatory oversight concept but it will require more development for the central tunnels, disposal tunnels and disposal holes which are the safety classified parts of the disposal facility.

Article will give an overview on the regulatory oversight of spent nuclear fuel encapsulation plant and underground disposal facility during the construction period and licensing of these nuclear facilities. Oversight during construction covers oversight of detailed design of systems, structures and component, feasibility demonstrations, construction activities for both facilities, monitoring the effects of construction of the underground disposal facility and commissioning of both facilities